### Choosing between application and network interceptors

Each interceptor chain has relative merits.

**Application interceptors**

 *  Fix: Change `Authenticator`'s `Route` parameter to be nullable. This was marked as non-null but
    could be called with null in some cases.
 *  Fix: Don't create malformed URLs when `MockWebServer` is reached via an IPv6 address.
 *  Fix: Don't crash if the system default authenticator is null.
 *  Fix: Don't crash generating elliptic curve certificates on Android.
 *  Fix: Don't crash doing platform detection on RoboVM.

     *     represented as a combination of scheme, host and port. When empty, the origin is that of
     *     the `streamId`.
     * @param protocol an ALPN protocol, such as `h2`.
     * @param host an IP address or hostname.
     * @param port the IP port associated with the service.
     * @param maxAge time in seconds that this alternative is considered fresh.
     */
    fun alternateService(
      streamId: Int,

    in logs. For best security, don't put sensitive information in query parameters.

 *  New: `ConnectionPool.setPolicy()` configures a minimum connection pool size for a target
    address. Use this to proactively open HTTP connections.

    Connections opened to fulfill this policy are subject to the connection pool's
    `keepAliveDuration` but do not count against the pool-wide `maxIdleConnections` limit.

    a malformed URL.)

 *  **We've improved connect failure recovery.** We now differentiate between
    setup, connecting, and connected and implement appropriate recovery rules
    for each. This changes `Address` to no longer use `ConnectionSpec`. (This is
    an incompatible API change).

 *  **`FormEncodingBuilder` now uses `%20` instead of `+` for encoded spaces.**

  /**
   * Returns the effective top-level domain plus one (eTLD+1) by referencing the public suffix list.
   * Returns null if the domain is a public suffix or a private address.
   *
   * Here are some examples:
   *
   * ```java
   * assertEquals("google.com", getEffectiveTldPlusOne("google.com"));
   * assertEquals("google.com", getEffectiveTldPlusOne("www.google.com"));

    val addressE = decodeIpv6("2001:db8::1:0:0:1")!!
    assertThat(canonicalizeInetAddress(addressE)).isEqualTo(addressE)

    val addressF = decodeIpv6("0:0:0:0:0:ffff:7f00:1")!!
    assertThat(canonicalizeInetAddress(addressF)).isEqualTo(addressB)

    val addressG = decodeIpv6("0:0:0:0:0:ffff:c0a8:1")!!
    assertThat(canonicalizeInetAddress(addressG)).isEqualTo(addressC)
  }

   *
   * When a URL is requested, it may be in the context of another URL.
   *
   *  * **Embedded resources like images and iframes** in browsers use the context as the page in
   *    the address bar and the subject is the URL of an embedded resource.
   *
   *  * **Potentially-destructive navigations such as HTTP POST calls** use the context as the page

    ).filter { it.isSupported() }

  @Throws(IOException::class)
  override fun connectSocket(
    socket: Socket,
    address: InetSocketAddress,
    connectTimeout: Int,
  ) {
    try {
      socket.connect(address, connectTimeout)
    } catch (e: ClassCastException) {
      // On android 8.0, socket.connect throws a ClassCastException due to a bug

    get() = codec.carrier as? RealConnection ?: error("no connection for CONNECT tunnels")

  internal val isCoalescedConnection: Boolean
    get() = finder.routePlanner.address.url.host != codec.carrier.route.address.url.host

  @Throws(IOException::class)
  fun writeRequestHeaders(request: Request) {
    try {
      eventListener.requestHeadersStart(call)
      codec.writeRequestHeaders(request)